/*
 * Copyright (c) 2024, Alibaba Cloud;
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.aliyun.dataworks.client.utils.spark.command;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Optional;
import java.util.concurrent.atomic.AtomicLong;
import java.util.logging.Level;
import java.util.logging.Logger;

class InProcessAppHandle extends AbstractAppHandle {

    private static final String THREAD_NAME_FMT = "spark-app-%d: '%s'";
    private static final Logger LOG = Logger.getLogger(InProcessAppHandle.class.getName());
    private static final AtomicLong THREAD_IDS = new AtomicLong();

    // Avoid really long thread names.
    private static final int MAX_APP_NAME_LEN = 16;

    private volatile Throwable error;

    private Thread app;

    InProcessAppHandle(LauncherServer server) {
        super(server);
    }

    @Override
    public synchronized void kill() {
        if (!isDisposed()) {
            LOG.warning("kill() may leave the underlying app running in in-process mode.");
            setState(State.KILLED);
            disconnect();

            // Interrupt the thread. This is not guaranteed to kill the app, though.
            if (app != null) {
                app.interrupt();
            }
        }
    }

    @Override
    public Optional<Throwable> getError() {
        return Optional.ofNullable(error);
    }

    synchronized void start(String appName, Method main, String[] args) {
        CommandBuilderUtils.checkState(app == null, "Handle already started.");

        if (appName.length() > MAX_APP_NAME_LEN) {
            appName = "..." + appName.substring(appName.length() - MAX_APP_NAME_LEN);
        }

        app = new Thread(() -> {
            try {
                main.invoke(null, (Object)args);
            } catch (Throwable t) {
                if (t instanceof InvocationTargetException) {
                    t = t.getCause();
                }
                LOG.log(Level.WARNING, "Application failed with exception.", t);
                error = t;
                setState(State.FAILED);
            }

            dispose();
        });

        app.setName(String.format(THREAD_NAME_FMT, THREAD_IDS.incrementAndGet(), appName));
        app.start();
    }

}
